For example, a glass run channel, which is mounted on a run mounting portion of a window frame that is provided along a window opening edge of a front door or a rear door of a vehicle and which guides moving up and down of a windowpane, is made of a rubber material or a polymer material (a thermoplastic elastomer material).
Further, a glass run channel, which is constituted of a foaming body that has countless foaming cells so as to achieve a reduction in weight of the glass run channel, is known.
Related-art discloses a glass run channel, in which microcapsules (thermal expansion capsules) are mixed with the rubber material, foamed and expanded.
Further, related-art discloses a glass run channel in which a chemical foaming agent is mixed to the polymer material, foamed and expanded.
In the related-art glass run channel made of foaming rubber, it is difficult to reduce the specific gravity and reduce the weight compared to the related-art glass run channel made of foamable polymer (made of thermoplastic elastomer).
Further, in the glass run channel made of foamable polymer, the chemical foaming agent is mixed with the polymer material, whereby expansion occurs. Thus, the countless foaming cells easily become opened cells that communicate with each other, and fluid, such as water, is easily absorbed.
Accordingly, after the polymer material that is mixed with the chemical foaming agent is extruded from an outlet of a mold of the extrusion molding machine and the molding body having a shape corresponding to the cross-sectional shape of the glass run channel is formed, when the molding body is, for example, cooled and solidified by coolant water in manufacturing the glass run channel, the glass run channel absorbs the coolant water.
Thus, after the glass run channel is cooled and solidified, a drying process is required so as to vaporize fluid that is absorbed within the glass run channel.
The glass run channel absorbs the fluid even in a use state in which the glass run channel is mounted on the run mounting portion of the window frame of the front door or the rear door. Thus, when outdoor temperature is a low temperature, fluid within the glass run channel is frozen and the glass run channel is excessively hardened so that there is a possibility that abnormal noise will be generated when the windowpane is moved up and down.